Hasil untuk "Petroleum refining. Petroleum products"

M. He, Yuhan Sun, B. Han

M. Masnadi, Hassan M. El-Houjeiri, Dominik Schunack et al.

New data enable targeted policy to lessen GHG emissions Producing, transporting, and refining crude oil into fuels such as gasoline and diesel accounts for ∼15 to 40% of the “well-to-wheels” life-cycle greenhouse gas (GHG) emissions of transport fuels (1). Reducing emissions from petroleum production is of particular importance, as current transport fleets are almost entirely dependent on liquid petroleum products, and many uses of petroleum have limited prospects for near-term substitution (e.g., air travel). Better understanding of crude oil GHG emissions can help to quantify the benefits of alternative fuels and identify the most cost-effective opportunities for oil-sector emissions reductions (2). Yet, while regulations are beginning to address petroleum sector GHG emissions (3–5), and private investors are beginning to consider climate-related risk in oil investments (6), such efforts have generally struggled with methodological and data challenges. First, no single method exists for measuring the carbon intensity (CI) of oils. Second, there is a lack of comprehensive geographically rich datasets that would allow evaluation and monitoring of life-cycle emissions from oils. We have previously worked to address the first challenge by developing open-source oil-sector CI modeling tools [OPGEE (7, 8), supplementary materials (SM) 1.1]. Here, we address the second challenge by using these tools to model well-to-refinery CI of all major active oil fields globally—and to identify major drivers of these emissions.

Yahui Miao, Ming-Ho To, Muhammad Ahmar Siddiqui et al.

Biosurfactants have garnered increased attention lately due to their superiority of their properties over fossil-derived counterparts. While the cost of production remains a significant hurdle to surpass synthetic surfactants, biosurfactants have been anticipated to gain a larger market share in the coming decades. Among these, glycolipids, a type of low-molecular-weight biosurfactant, stand out for their efficacy in reducing surface and interfacial tension, which made them highly sought-after for various surfactant-related applications. Glycolipids are composed of hydrophilic carbohydrate moieties linked to hydrophobic fatty acid chains through ester bonds that mainly include rhamnolipids, trehalose lipids, sophorolipids, and mannosylerythritol lipids. This review highlights the current landscape of glycolipids and covers specific glycolipid productivity and the diverse range of products found in the global market. Applications such as bioremediation, food processing, petroleum refining, biomedical uses, and increasing agriculture output have been discussed. Additionally, the latest advancements in production cost reduction for glycolipid and the challenges of utilizing second-generation feedstocks for sustainable production are also thoroughly examined. Overall, this review proposes a balance between environmental advantages, economic viability, and societal benefits through the optimized integration of secondary feedstocks in biosurfactant production.

Xu Yan, Jiale Wang, Rou Wen et al.

The utilization of microorganisms to transform biomass into biofuels and biochemicals presents a viable and competitive alternative to conventional petroleum refining processes. Halomonas species are salt-tolerant and alkaliphilic, endowed with various beneficial properties rendering them as contamination resistant platforms for industrial biotechnology, facilitating the commercial-scale production of valuable bioproducts. Here we summarized the metabolic and genomic engineering approaches, as well as the biochemical products synthesized by Halomonas. Methods were presented for expanding substrates utilization in Halomonas to enhance its capabilities as a robust workhorse for bioproducts. In addition, we briefly reviewed the Next Generation Industrial Biotechnology (NGIB) based on Halomonas for open and continuous fermentation. In particular, we proposed the industrial attempts from Halomonas chassis and the rising prospects and essential strategies to enable the successful development of Halomonas as microbial NGIB manufacturing platforms.

R. Kumar

European Union (EU) and the G7 Nations imposed sanctions on Russia in December 2022 and introduced a price cap and an embargo on the imports of the Russian Crude Oil. This was with aim to restrict war funding of Russia for the invasion of Ukraine. Since then a significant realignment in global energy trade and shift in Russian oil market has emerged. India has limited energy resources but with growing economy and social responsibility has very high energy demand. It cannot afford higher price of petroleum products. In case, the Russian Oil was out of market, the petroleum product cost would have gone beyond affordable means of the country. Accordingly India has made use of this opportunity and has increased its crude refining capacity to meet its own energy demand and to become EUs largest supplier of refined fuels, mainly sourced from discounted Russian Crude. In bargain India has earned much valued foreign exchange, and earned profits on imports of oil, which was unheard prior to COVID-19 period. The increase of refining capacity is in confirmation with India’s ‘Atma Nirbhar Bharat’ and ‘Make in India’ initiative. Indian’s crude refining infrastructure can cater for refining capacity of more than 257 MMPTA through its PSU refinery, joint venture refineries and Private Sector Refineries. This paper examines the strategic, economic and geopolitical dynamics for this trend, highlights the role of India’s Refining capability enhancements, the problems related to regulatory loopholes in EU Sanctions and the broader aspect of Energy security for India. It also gives future prospects and recommendations for Indian Government and associated private players in the industry.

DING Jiaqian, LIU Haitao, SUN Jianmeng et al.

Accurate evaluation of cementing quality plays a crucial role in ensuring the safety and efficiency of oil and gas field development. To address the limitations of traditional methods in dual-casing wells, this study proposes a cementing quality evaluation method for dual-casing wells based on continuous wavelet transform (CWT). This paper systematically elaborates on the basic theory of CWT, uses the Morlet wavelet as the basis function to perform time-frequency transformation and in-depth analysis on actual well logging data, and extracts multi-dimensional characteristic parameters such as first arrival time and amplitude. It clarifies the thresholds and judgment logic for characteristic parameters, establishes a multi-scale time-frequency analysis framework and quantitative identification criteria for the cementation state at the multi-interfaces (casing-cement sheath-formation), and conducts comparative verification by combining numerical simulations and logging data from single-casing and dual-casing wells. The research results show that: ① It successfully distinguishes different states, including good cementation at all interfaces and poor cementation at 1 to 4 interfaces, and identifies the differences in time-frequency characteristics under different cementation states. For example, when cementation is good, obvious formation waves exist in the frequency band of 8～12 kHz; when cementation at the first interface is poor, the energy in the time window of 0.30～0.45 ms and frequency band of 15～30 kHz exceeds the threshold of 500. ② In the application of the 35～220 m interval of Well A, it is found that the proportion of poor cementation at the second and third interfaces is significantly higher than that of other interfaces. Poor cementation at the third interface occurs concentratedly in the 110～150 m interval; continuous poor cementation at the second interface appears in the 65～70 m and 72～82 m intervals; and continuous poor cementation at the fourth interface is observed in the 195～220 m interval. ③ Compared with traditional methods, the adaptability of the proposed method to complex formations is significantly improved. It can accurately distinguish the cementation quality of the second and third interfaces, which are difficult to judge by traditional methods, and solves the problems of reduced resolution and insufficient collaborative evaluation of multi-interfaces in traditional methods. ④ Through the comparison between simulated data and actual data, the reliability of the quantitative relationship model is verified, and the evaluation results of poor cementation at the four interfaces of dual-casing wells are in good agreement with those of single-casing wells. It is concluded that this quantitative evaluation method based on CWT provides an effective new approach for cementing quality evaluation of dual-casing wells, significantly improves the accuracy and reliability of evaluation, and promotes the development of related evaluation technologies in oil and gas exploration and development.

Kanishk Bhatia, Felix Koehler, Nils Thuerey

The physics solvers employed for neural network training are primarily iterative, and hence, differentiating through them introduces a severe computational burden as iterations grow large. Inspired by works in bilevel optimization, we show that full accuracy of the network is achievable through physics significantly coarser than fully converged solvers. We propose Progressively Refined Differentiable Physics (PRDP), an approach that identifies the level of physics refinement sufficient for full training accuracy. By beginning with coarse physics, adaptively refining it during training, and stopping refinement at the level adequate for training, it enables significant compute savings without sacrificing network accuracy. Our focus is on differentiating iterative linear solvers for sparsely discretized differential operators, which are fundamental to scientific computing. PRDP is applicable to both unrolled and implicit differentiation. We validate its performance on a variety of learning scenarios involving differentiable physics solvers such as inverse problems, autoregressive neural emulators, and correction-based neural-hybrid solvers. In the challenging example of emulating the Navier-Stokes equations, we reduce training time by 62%.

Sandra Kiefer, T. Devini de Mel

The Colour Refinement algorithm is a classical procedure to detect symmetries in graphs, whose most prominent application is in graph-isomorphism tests. The algorithm and its generalisation, the Weisfeiler-Leman algorithm, evaluate local information to compute a colouring for the vertices in an iterative fashion. Different final colours of two vertices certify that no isomorphism can map one onto the other. The number of iterations that the algorithm takes to terminate is its central complexity parameter. For a long time, it was open whether graphs that take the maximum theoretically possible number of Colour Refinement iterations actually exist. Starting from an exhaustive search on graphs of low degrees, Kiefer and McKay proved the existence of infinite families of such long-refinement graphs with degrees 2 and 3, thereby showing that the trivial upper bound on the iteration number of Colour Refinement is tight. In this work, we provide a complete characterisation of the long-refinement graphs with low (or, equivalently, high) degrees. We show that, with one exception, the aforementioned families are the only long-refinement graphs with maximum degree at most 3, and we fully classify the long-refinement graphs with maximum degree 4. To this end, via a reverse-engineering approach, we show that all low-degree long-refinement graphs can be represented as compact strings, and we derive multiple structural insights from this surprising fact. Since long-refinement graphs are closed under taking edge complements, this also yields a classification of long-refinement graphs with high degrees. Kiefer and McKay initiated a search for long-refinement graphs that are only distinguished in the last iteration of Colour Refinement before termination. We conclude it in this submission by showing that such graphs cannot exist.

Wennan Long, Diego Moya, Zemin Eitan Liu et al.

The transition toward a low-carbon maritime transportation requires understanding lifecycle carbon intensity (CI) of marine fuels. While well-to-tank emissions significantly contribute to total greenhouse gas emissions, many studies lack global perspective in accounting for upstream operations, transportation, refining, and distribution. This study evaluates well-to-tank CI of High Sulphur Fuel Oil (HSFO) and well-to-refinery exit CI of Liquefied Petroleum Gas (LPG) worldwide at asset level. HSFO represents traditional marine fuel, while LPG serves as potential transition fuel due to lower tank-to-wake emissions and compatibility with low-carbon fuels. Using OPGEE and PRELIM tools with R-based geospatial methods, we derive country-level CI values for 72 countries (HSFO) and 74 countries (LPG), covering 98% of global production. Results show significant variation in climate impacts globally. HSFO upstream CI ranges 1-22.7 gCO2e/MJ, refining CI 1.2-12.6 gCO2e/MJ, with global volume-weighted-average well-to-tank CI of 12.4 gCO2e/MJ. Upstream and refining account for 55% and 32% of HSFO well-to-tank CI, with large exporters and intensive refining practices showing higher emissions. For LPG, upstream CI ranges 0.9-22.7 gCO2e/MJ, refining CI 2.8-13.9 gCO2e/MJ, with volume-weighted-average well-to-refinery CI of 15.6 gCO2e/MJ. Refining comprises 49% of LPG well-to-refinery CI, while upstream and transport represent 44% and 6%. Major players include China, United States and Russia. These findings reveal significant CI variability across countries and supply chains, offering opportunities for targeted emission reduction policies.

XU Ning, CHEN Zhewei, XU Wanchen et al.

Energy storage volume fracturing is a pivotal early development technique for shale reservoirs, designed to supplement reservoir energy preemptively and significantly boost single well production. A method for predicting the maximum cumulative oil production during the development stage of energy storage fracturing is proposed, based on the mechanisms of imbibition and displacement coupled with the statistical analysis of actual production data. The results demonstrate that following a 30% flowback ratio, the cumulative oil production from energy storage fracturing exhibits a strong linear relationship with the logarithm of the flowback ratio. This relationship can predict the maximum cumulative oil production of a single well after fracturing. Validated by actual production data from other shale reservoirs, this method proves to be more accurate and universal than the decline curve analysis method. It encompasses a comprehensive evaluation of subjective and objective factors such as reservoir conditions, fracturing scale and technology, production system design, and drainage efficiency. Additionally, the method facilitates the determination of the liquid-to-oil ratio and the reasonable flowback rate. By controlling the average rate of discharge and production within the range of 6~8 m³/（d·km）, which aligns with the rates of oil drainage and imbibition, higher oil recovery and a lower liquid-to-oil ratio are achieved. This prediction method for maximum recoverable oil post-single well fracturing provides a basis for the economic benefit evaluation, production system optimization, and fracturing cost control of energy storage fracturing. It holds significant guiding importance for geological-engineering integration, well spacing optimization, and fracturing design.

Gongcheng ZHANG, Dianjun TONG, Kai CHEN et al.

The Bohai Bay Basin, as a super oil-rich basin in the world, is characterized by cyclic evolution and complex regional tectonic stress field, and its lifecycle tectonic evolution controls the formation of regional source rocks. The main pre-Cenozoic stratigraphic system and lithological distribution are determined through geological mapping, and the dynamics of the pre-Cenozoic geotectonic evolution of the Bohai Bay Basin are investigated systematically using the newly acquired high-quality seismic data and the latest exploration results in the study area. The North China Craton where the Bohai Bay Basin is located in rests at the intersection of three tectonic domains: the Paleo-Asian Ocean, the Tethys Ocean, and the Pacific Ocean. It has experienced the alternation and superposition of tectonic cycles of different periods, directions and natures, and experienced five stages of the tectonic evolution and sedimentary building, i.e. Middle–Late Proterozoic continental rift trough, Early Paleozoic marginal-craton depression carbonate building, Late Paleozoic marine–continental transitional intracraton depression, Mesozoic intracontinental strike-slip–extensional tectonics, and Cenozoic intracontinental rifting. The cyclic evolution of the basin, especially the multi-stage compression, strike-slip and extensional tectonics processes in the Hercynian, Indosinian, Yanshan and Himalayan since the Late Paleozoic, controlled the development, reconstruction and preservation of several sets of high-quality source rocks, represented by the Late Paleozoic Carboniferous–Permian coal-measure source rocks and the Paleogene world-class extra-high-quality lacustrine source rocks, which provided an important guarantee for the hydrocarbon accumulation in the super oil-rich basin.

Sun Dianxin

The vane type multiphase pump is prone to produce vane tip leakage vortex and gas-liquid separation under gas-liquid conditions,which directly leads to reduced pump performance,thereby affecting the pump delivery efficiency and increasing the production costs.To solve these problems,based on CFD simulation,the splitter vanes of pump impeller were modified,and the influence of the front shape of splitter vanes on pump performance was investigated.The results show that the models with 3 front shapes of splitter vanes yield higher delivery head than the original model.Typically,the model with continuously curved splitter vane has the highest delivery head of 10.85 m and the efficiency of 33.76%,which are 31.83% and 2.58% respectively higher than the original model.When the thickness of the splitter vanes decreases,the ability of the front half of the splitter vane to suppress medium separation is improved,and the adhesion of the liquid phase on the suction surface of the splitter vane is enhanced.Affected by the suppressed banded leakage vortex,the turbulence degree of medium flow in the impeller is low in case of continuously curved splitter vane,and the suppression is quantified as 5.07% liquid phase drag reduction and 3.80% gas phase drag reduction at the impeller eye.The research results provide reference for the subsequent optimization design of multiphase pumps.

Xizi Wang, Feng Cheng, Ziyang Wang et al.

Video temporal grounding aims to localize relevant temporal boundaries in a video given a textual prompt. Recent work has focused on enabling Video LLMs to perform video temporal grounding via next-token prediction of temporal timestamps. However, accurately localizing timestamps in videos remains challenging for Video LLMs when relying solely on temporal token prediction. Our proposed TimeRefine addresses this challenge in two ways. First, instead of directly predicting the start and end timestamps, we reformulate the temporal grounding task as a temporal refining task: the model first makes rough predictions and then refines them by predicting offsets to the target segment. This refining process is repeated multiple times, through which the model progressively self-improves its temporal localization accuracy. Second, to enhance the model's temporal perception capabilities, we incorporate an auxiliary prediction head that penalizes the model more if a predicted segment deviates further from the ground truth, thus encouraging the model to make closer and more accurate predictions. Our plug-and-play method can be integrated into most LLM-based temporal grounding approaches. The experimental results demonstrate that TimeRefine achieves 3.6% and 5.0% mIoU improvements on the ActivityNet and Charades-STA datasets, respectively. Code and pretrained models will be released.

Ivan Gilardoni, Valerio Piomponi, Thorben Fröhlking et al.

Molecular dynamics (MD) simulations play a crucial role in resolving the underlying conformational dynamics of molecular systems. However, their capability to correctly reproduce and predict dynamics in agreement with experiments is limited by the accuracy of the force-field model. This capability can be improved by refining the structural ensembles or the force-field parameters. Furthermore, discrepancies with experimental data can be due to imprecise forward models, namely, functions mapping simulated structures to experimental observables. Here, we introduce MDRefine, a Python package aimed at implementing the refinement of the ensemble, the force-field and/or the forward model by comparing MD-generated trajectories with experimental data. The software consists of several tools that can be employed separately from each other or combined together in different ways, providing a seamless interpolation between these three different types of refinement. We use some benchmark cases to show that the combined approach is superior to separately applied refinements. Source code, documentation and examples are freely available at https://pypi.org/project/MDRefine and https://github.com/bussilab/MDRefine.

Florian Kammüller

In this paper, we add a second part to the process of Security Engineering to the Isabelle Insider and Infrastructure framework (IIIf) [31,16] by addressing an old difficult task of refining Information Flow Security (IFC). We address the classical notion of Noninterference representing absolute security in the sense of absence of information flows to lower levels. This notion is known to be not preserved by specification refinements in general, a phenomenon known as "refinement paradox" [33]. We use a solution for this problem that has been given by Morgan [33] for the refinement calculus for sequential program specifications and generalize it to general specifications of Infrastructures with actors, decentralization and policies in the IIIf. As a running example to illustrate the problem, the concepts and the solution, we use an example of a Flightradar system specification [20].

Parthasarathy Srinivasan

There have been several modifications of how basic calculus has been taught, but very few of these modifications have considered the computational tools available at our disposal. Here, we present a few tools that are easy to develop and use. Doing so also addresses a different way to view calculus, and attempts to fill the gaps in students' understanding of both differentiation and integration. We will describe the basics of both these topics in a way that might be much more useful and relevant to students, and hence possible ways in refining calculus pedagogy to make calculus more accessible to them. For integration, an elementary development of Gaussian quadrature using basic linear algebra is presented. This numerical method can be extended to integrate functions over various domains in higher dimensions, a subject that is not currently well covered in multivariable calculus or other Mathematics courses. We also briefly discuss series that may be more useful than some of those taught in current calculus courses.

Tang Ruihuan

As the number of ultra-deep and long horizontal wells of unconventional oil and gas continuously increase,the reservoir reconstruction technology for oil and gas exploitation is also continuing to follow up,thus promoting the development of fracturing equipment in the direction of high power,high load,continuous operation and intelligence.Sichuan-Chongqing block is the main battlefield of shale gas development in the “14th Five-Year Plan” in China.On the basis of introducing the operation status of traditional fracturing equipment,this paper analyzed its shortcomings in shale gas fracturing in Sichuan-Chongqing area,pointed out that fracturing equipment would develop in the direction of electric fracturing equipment and turbine fracturing equipment,conducted outlook on application of fault state monitoring and diagnosis system of fracturing set,fracturing energy storage(power transformation)system technology and low-voltage integrated Internet of Things(IOT)system technology in fracturing equipment,and further pointed out the development direction of fracturing technology and equipment in China,i.e.,development in the direction of environmental optimization,light weight and automation.The conclusions provide reference for the efficient development of shale gas and the field application and optimization of fracturing equipment in Sichuan-Chongqing area in China.

Bowen Shi, Jiajun Hong, Zhihua Wang et al.

Abstract As deep gas-condensate reservoirs are explored, the problem of paraffin deposition is becoming more prominent. Therefore, this paper collects condensate samples from representative paraffin deposition gas-condensate wells and analyzes basic physical properties. The cold plate deposition device is employed to study paraffin deposition behavior under well conditions and to divide the critical regions for paraffin deposition in gas-condensate wells. The experimental apparatus, such as the crude oil dynamic paraffin deposition rate tester, is utilized to investigate the preventive effect of paraffin dispersants and paraffin crystal modifier. The results show that there is significant phase change behavior in gas-condensate wells and gas phase is dominant form, but there is also phase evolution. It can be identified from the experiments that paraffin deposition is mainly located in the 1000 ~ 1500 m region, and a paraffin deposition identification chart has been established. The maximum deposition rate could reach 15.50 mm/year, which matched the temperature and pressure conditions of 45 ℃ and 70 MPa. The preventive effect of paraffin crystal modifiers greatly exceeds that of paraffin dispersants, with paraffin prevention rates of 85–95% at the optimal concentrations of 0.25–0.50 wt.%. The dissolving paraffin rate can reach 0.0169 g/min. It decreases the paraffin appearance temperature approximately 40% and significantly changes the paraffin crystal morphology. Increased deposition surface area of the cold plate structural design describes the paraffin deposition. This diagram facilitates the reliable identification of paraffin deposition areas and the deposition rates in the wellbore during production. The optimum amounts of BZ and PI paraffin inhibitors are quantified. This study provides a comprehensive understanding of the paraffin deposition behavior, and scientific basis and guidance for the selection of paraffin inhibitors in gas-condensate wells.

Osamah ALOMAIR, Mabkhout AL-DOUSARI, C. Nyeso AZUBUIKE et al.

This study investigated experimentally the coupled effects of hydrophilic SiO2 nanoparticles (NPs) and low-salinity water (LSW) on the wettability of synthetic clay-free Berea sandstone. Capillary pressure, interfacial tension (IFT), contact angle, Zeta potential, and dynamic displacement measurements were performed at various NP mass fractions and brine salinities. The U.S. Bureau of Mines (USBM) index was used to quantify the wettability alteration. Furthermore, the NP stability and retention and the effect of enhanced oil recovery by nanofluid were examined. The results showed that LSW immiscible displacement with NPs altered the wettability toward more water wet. With the decreasing brine salinity and increasing NP mass fraction, the IFT and contact angle decreased. The wettability alteration intensified most as the brine salinity decreased to 4000 mg/L and the NP mass fraction increased to 0.075%. Under these conditions, the resulting incremental oil recovery factor was approximately 13 percentage points. When the brine salinity was 4000 mg/L and the NP mass fraction was 0.025%, the retention of NPs caused the minimum damage to permeability.

Seunghwan Lee, Gwanmo Park, Hyewon Son et al.

We introduce InFusionSurf, an innovative enhancement for neural radiance field (NeRF) frameworks in 3D surface reconstruction using RGB-D video frames. Building upon previous methods that have employed feature encoding to improve optimization speed, we further improve the reconstruction quality with minimal impact on optimization time by refining depth information. InFusionSurf addresses camera motion-induced blurs in each depth frame through a per-frame intrinsic refinement scheme. It incorporates the truncated signed distance field (TSDF) Fusion, a classical real-time 3D surface reconstruction method, as a pretraining tool for the feature grid, enhancing reconstruction details and training speed. Comparative quantitative and qualitative analyses show that InFusionSurf reconstructs scenes with high accuracy while maintaining optimization efficiency. The effectiveness of our intrinsic refinement and TSDF Fusion-based pretraining is further validated through an ablation study.